Answer:
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
Explanation:
Answer:
Both A and B
Explanation:
The interaction of magnetic fields and armature results into a rotational force of the armature hence turning motion. It's important to note that you will always need two magnetic fields in order to experience the force since one magnetic field is at the rotating armature and another at the casing. Considering the arguments of these two technicians, both of them are correct in their arguments.
Answer:
Explanation:
Given
mass of children 

distance between two children 
suppose small child is at a distance of x m from pivot point
so torque of small child and heavier child must be equal



Answer:
Speed of gamma rays = 3 x 10⁸ m/s
Explanation:
Given:
Frequency of gamma ray = 3 x 10¹⁹ Hz
Wavelength of gamma rays = 1 x 10⁻¹¹ meter
Find:
Speed of gamma rays
Computation:
Velocity = Frequency x wavelength
Speed of gamma rays = Frequency of gamma ray x Wavelength of gamma rays
Speed of gamma rays = [3 x 10¹⁹][1 x 10⁻¹¹]
Speed of gamma rays = 3 x [10¹⁹⁻¹¹]
Speed of gamma rays = 3 x [10⁸]
Speed of gamma rays = 3 x 10⁸ m/s